Bucaniidae (Gastropoda) from the Upper Ordovician of Norway

Abstract

Fourteen species of bellerophontoid gastropods of the Family Bucaniidae are described from the Upper Ordovician succession of the Oslo Region, Norway. Bucania sp. is compared with several species of Bucania that stand out morphologically by having a median dorsal carina, moderate to wide umbilici and an ornamentation consisting of crenulated growth lines. Salpingostoma carnatum sp. nov. from the Kalvsjøen Formation in Hadeland illustrates the problems of generic delimitation within the Bucaniidae by showing morphological characters similar to both Bucania and Salpingostoma. Megalomphala crassiuscula Koken, 1897 is figured for the first time, but the species may eventually prove to be conspecific with M. contorta (d'Eichwald, 1856). Based on new material, the poorly known species Phragmolites pinguis (Koken in Koken & Perner, 1925) is transferred to Megalomphala. Norwegian material of Tetranota conspicua (d'Eichwald, 1840) is conspecific with the Estonian form sensu lato, though the original Estonian concept of this conspicuous Baltic species needs to be revised.